The Single Cell Profiling Core of the DFCI-PSOC is a virtual infrastructure led by Dr. Fan who has been serving in this role since 2012 for the current DFCI-PSOC. The core provides the capability of characterizing single cells at the omics level in order to dissect intra-clonal cellular heterogeneity, discover molecular correlates, and refine the parameters used to gauge tumor cell fitness in computational modeling. Specifically, the core will support all three projects, focused on hematologic, brain and breast cancer, respectively, by offering services to measure the transcriptome, epigenome, and proteomic signatures in single cells isolated from either `winner' clones or therapeutically resistant clones. Because fractional killing is common even within individual clones, it is highly desired to conduct single cell profiling in conjunction with computational analysis to identify molecular correlates associated with the most aggressive fraction and refine the parameters for modeling tumor cell fitness. While researchers in individual projects will carry out tracking clonal growth and molecular signature changes of each clone, the core will characterize cellular heterogeneity within individual clones, especially at the omics level, which remains challenging. The core is positioned to address this critical need and to enhance the PSOC's ability to probe cancer clonal evolution in a more systematic and granular manner. In parallel, the core is a technology innovation center that aims to develop new technology platforms (e.g., single cell methylome profiling, single cell protein secretome profiling) to enable new opportunities of scientific discoveries that cannot be achieved using the existing tools.